Braking in new Ring and Pinion

[barCruiser]

I installed new gears over the weekend (4.88's), and was wondering if there are any special steps that need to be taken to break in the gears.

[WarDamnEagle]

Most of the recommendations that I have read say to drive it gently a few miles (10 to 20) and then let everything cool down for a couple of hours. When you first drive with the gears they will generate a lot of heat. You need to let them set against each other (which involves the self-removal of a bit of metal) and this process generates the heat. The danger of driving further prior to letting them cool is that you will adversly degrade the diff oil and/or burn the paint off your axles or worse.

I have also seen it recommended that you do this process a couple of times and then drive normally (without towing) for the first 500 miles +/-. You should then change the differential oil and call it good. Don't be surprised if you find quite a bit of metal fines on your drain plug magnet when pull the drains.

[Cruiserdrew]

I agree with the above. The first time you drive-keep it short and slow. I drove 3 miles to the local pub, had a beer with my install help, and drove home. Then I drove back and forth to work for a week, 3 miles each way. Then a couple of 10-15 mile trips including a few freeway miles. I changed gear oil at 100 miles and 500 miles. I don't think I exceeded 55 mph for 500 miles. Those same gears are still running today 60,000 miles later nice and quiet with no issues. I never really had much in the way of metal filings or dust.

Just keep it slow and short for at least the first 100 miles and continue to be gentle for 500 miles. It should be fine.

[ringpinion.biz]

New Gear Break-In
All new gear sets require a break-in period to prevent damage from overheating. Any overloading or overheating will cause the gear oil to break down and the ring & pinion will fail. Please follow these guidelines to insure proper break-in.

· After light use for the first 15 to 20 miles it is best to stop and let the differential cool before proceeding.
· Avoid heavy acceleration during the break-in process.
· J.T.’s warranty requires at least 500 miles before towing.
· J.T.’s also requires towing for very short distances (less than 15 miles) and letting the differential cool before continuing during the first 45 towing miles.
J.T.’s recommends changing the oil after the first 500 miles. This will remove any metal particles or phosphorous coating that has come from the new gear set.

This may seem unnecessary but it is very easy to damage the differential by loading it before the gear set is completely broken in. The greatest damage results when a new ring & pinion has been run for several miles during the first 500 miles and the oil is very hot.

Originally Posted by barCruiser

I installed new gears over the weekend (4.88's), and was wondering if there are any special steps that need to be taken to break in the gears.

[motorsargeT]

Originally Posted by ringpinion.biz

New Gear Break-In
All new gear sets require a break-in period to prevent damage from overheating. Any overloading or overheating will cause the gear oil to break down and the ring & pinion will fail. Please follow these guidelines to insure proper break-in.

· After light use for the first 15 to 20 miles it is best to stop and let the differential cool before proceeding.
· Avoid heavy acceleration during the break-in process.
· J.T.’s warranty requires at least 500 miles before towing.
· J.T.’s also requires towing for very short distances (less than 15 miles) and letting the differential cool before continuing during the first 45 towing miles.
J.T.’s recommends changing the oil after the first 500 miles. This will remove any metal particles or phosphorous coating that has come from the new gear set.

This may seem unnecessary but it is very easy to damage the differential by loading it before the gear set is completely broken in. The greatest damage results when a new ring & pinion has been run for several miles during the first 500 miles and the oil is very hot.

This is the instructions I recieved with my gears(Thanks J.T.'s) which I followed exactly except I did 1 extra drain and fill of the gear oil after 50 miles because I am anal and didn't want that extra metal floating around my new bearings for 500 miles.

[barCruiser]

Thanks for all the replies, sounds like a pretty easy break-in procedure. Any thoughts on what type of oil to use? I was planning on just using the cheapo 90w dino oil for the first 500 mi. then switching to M1 synthetic.

[WarDamnEagle]

I think either 75W-90, 80W-90 or straight 90w would be fine for the first fill. I would then switch to synthetic. I use Redline 75W-90NS but can't say that I'm a strong advocate. Use M1, Amsoil, Redline or whatever flavor synthetic floats your boat....others may have stronger opinions.

[Cruiserdrew]

The gear guy here just recommended Valvoline 80w-90. As long as it's GL-5, I don't think it really matters.